Currently, CA-210 Color Analyzer, commercially available from Konica Minolta Corporation, Japan, is used to manually measure transmittance of a touch sensor in a liquid crystal display (LCD). Generally, the measurement is carried out by means of choosing randomly and testing five points on the touch sensor. However, such manually testing method can not guarantee uniformity of positions and distances between the CA-210 Color Analyzer and the touch sensor, and therefore such testing results are in low accuracy.